Tension control device

ABSTRACT

Disclosed is a tension control device for spooled filamentary material which includes a support structure, a spool support for the filamentary material rotatably carried by the support structure, and a rotatable pivot shaft. A first lever fixed on the shaft carries a guide means for tensioning the filamentary material withdrawn from the device and a brake which engages the spool support. A second lever is fixed on the pivot shaft and carries an adjustable loading device which applies a predetermined load to the first lever to maintain a constant tension in the filamentary material.

[4 1 Aug. 12, 1975 Primary Examiner-Robert J. Spar AssistantExaminerKenneth Noland Attorney, Agent, or FirmHami1ton, Renner & Kenner[57] ABSTRACT Disclosed is a tension control device for spooledfilamentary material which includes a support structure, a spool supportfor the filamentary material rotatably carried by the support structure,and a rotatable pivot shaft. A first lever fixed on the shaft carries aguide means for tensioning the filamentary material withdrawn from thedevice and a brake which engages the spool support. A second lever isfixed on the pivot 558 Princeton St., Barberton, Ohio 44203 Jan. 10

Appl. No.: 432,133

TENSION CONTROL DEVICE Inventor: Raymond J. Slezak,

US. Cl. 242/1562; 242/7543; 254/173 Int. Field of Search 254/149References Cited UNITED STATES PATENTS United States Patent Slezak [22]Filed:

shaft and carries an adjustable loading device which applies apredetermined load to the first lever to maintain a constant tension inthe filamentary material.

6 Claims, 2 Drawing Figures 10/1956 1/1959 .lurs et a1. 3/1959Nelson............................. 2,983,468 5/1961Perre1la............................ 3,076,618 2/1963 Hook 3,081,9573/1963 Van De Bi1t.. 3,355,122 11/1967Thatcher........................t.

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TENSION CONTROL DEVICE BACKGROUND OF THE INVENTION This inventionrelates to an automatic tension control device for regulating the amountof tension under which a filamentary material is withdrawn from a spool.The device is capable of maintaining a substantially uniform andpreselected tension in a filamentary material, although more readilyadjustable, structurally less complex, more responsive under certaincircumstances, and otherwise advantageous in comparison with known priorart devices designed to so function.

Filamentary materials include single and multiple strand fibers producedin long lengths and conveniently wound on spools. The various filamentsmay be either natural or synthetic fibers, glass or metal. Suchmaterials are commonly utilized as reinforcements for plastic orelastomeric compounds or they themselves may be fabricated into integralitems as in the textile industry. Regardless of the application it iscustomary to withdraw the filamentary material from the spool at or nearthe location it is being used. To facilitate such removal, the spool iscustomarily mounted on a spindle or creel assembly which permits thespool to rotate as the filament is withdrawn.

Because payout of the filament from the spool may be at a high linearvelocity thereby imparting substantial momentum to the spool and relatedspindle mounting components, it is necessary to dissipate force rapidlyin the event the filament breaks or the takeup sud- .denly decreases. Ineither situation, filament will be payed out more rapidly than it isneeded until rotation of the spool can compensate. Obviously, theproblem is greatly multiplied when a creel assembly carrying up toseveral hundred spools is being used.

Numerous braking devices have been developed for use with creels. Manyof these provide for the filament to be payed out under tension greaterthan what is required for payout from the spool. As the tensiondecreases, with slack in the filament, a braking force is SUMMARY OF THEINVENTION It is therefore an object of the present invention to providea tension control device which provides for payout of filamentarymaterial at a uniform tension selected from a substantial rangeirrespective of the rate at which the filament is taken up.

It is another object of the present invention to provide a tensioncontrol device which maintains substantially uniform tension on a spoolof filamentary material from full to empty spool condition.

It is a further object of the present invention to provide a tensioncontrol device which is relatively com pact and readily adjusted so asto accommodate various filamentary materials.

It is yet another object of the present invention to provide a tensioncontrol device which may be loaded by air pressure regulation to providea plurality of predetermined tension settings and, other than during thechanging of settings, does not require an air flow as no air isconsumed.

It is still another object of the present invention to provide a tensioncontrol device or plurality thereof the selected tension of which may bereadily varied remotely by a single adjustment.

It is a further object of the present invention to provide a tensioncontrol device which exhibits a minimum of hunting or loping in the formof periodic variations about a selected tension setting substantiallyirrespective of how high the tension setting, eccentricities in thespools, and related factors.

It is a still further object of the present invention to provide atension control device the operation of which is within normal operatinglimits substantially independent of the coefficient of friction betweenbraking components.

These and other objects of the present invention, together with theadvantages thereof over existing and prior art forms which will becomeapparent from the following description, are accomplished by the meanshereinafter described and claimed.

In general, a tension control device for spooled filamentary materialincludes a support structure, a spool support for the filamentarymaterial rotatably carried by the support structure, and a rotatableshaft. A first lever is fixed on the shaft. A filament guide carried bythe first lever is bodily movable therewith as the filamentary materialpasses from the device, and a brake carried by the first leverselectively frictionally engages the spool support in response tochanges in tension of the filamentary material as it passes over theguide. A second lever is also fixed on the shaft, and carries anadjustable loading device which applies a predetermined load to thefirst lever to maintain constant tension on the filamentary material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation of thetension control device depicting movement of the first and second leversin phantom and a spool of filamentary material, also in phantom; and,

FIG. 2 is a side elevation depicting the guide means and the means forcontrolling the amount of tension necessary for braking of the spoolsupporting means.

DESCRIPTION OF THE PREFERRED EMBODIMENT The tension control device,indicated generally by the numeral 10, includes a support structure,generally indicated by the numeral 11, upon which is mounted a spoolsupport, generally indicated by the numeral 12. First and second levers,13 and 14 respectively, are fixed on a pivot shaft 15 rotatably carriedby the support structure 11. The first lever 13 carries a guide rollerl6 and a brake shoe l8, and an air cylinder 19, is connected to thesecond lever.

The support structure 11 includes a rectangularly shaped plate 20 whichmay be bolted to a suitable frame assembly (not shown) upon which aplurality of devices 10 may be arranged. Axially extending from theplate 20 is a cylindrical hub 21 which in turn supports two radiallyextending arms, as shown laterally extending arm 22, and downwardlyextending arm 23. As depicted in FIG. 2, the hub 21 and plate 20 neednot be perpendicularly related one to the other, thereby allowing aspool of filamentary material 24, depicted in phantom, to be upwardlyinclined from the device as the filament is withdrawn so that it remainsseated against the spool support described hereinafter. Of course, thisangular relationship between the plate and hub 21 may be varied duringassembly pursuant to the specific requirements of a given application.

The spool support 12 includes a spindle 25 which extends into the hub 21being rotatably mounted therein with anti-friction bearings. The spindle25 is of a suitable length and diameter so as to pass through the centerof spool 24, and if desired, it may itself receive a larger spindle toproperly fit varying spool dimensions. Mounted on the spindle 25 androtatable therewith is a circular backing plate 26 which may be providedwith a spacer 28 to maintain the spool 24 away from the plate 26. Atleast one guide pin 29 is threadably mounted in said backing plate 26and is engageable with a bore in the spool 24 whereby the backing plate26, spindle 25 and spool 24 will rotate as one when the filament iswithdrawn. If desired, a second pin may be substituted for the bolt 30which passes through spacer 28. A bearing 31 maintains the backing plate26 a fixed distance from the hub 21. The circular backing plate 26functions as a brake drum, as will be described hereinbelow, and has asmooth circumferential braking surface 32, facilitating the desiredbraking in response to changes in tension occurring with variances inthe rate of filament takeup.

Attached to the end portion of the arm 23, extending from the hub 21, isa cylindrical housing 33 which receives the shaft 15, freely rotatabletherein. On the outboard end of the shaft 15, i.e., away from the plate20, the elongated, curved control lever 13 is secured, the lever 13having a bore 34 for receipt of the shaft 15.

As depicted in FIG. 1, thecontrol lever 13 is pivotable toward and awayfrom the spindle 25. The control lever 13 terminates a short distancebeyond its connection with the shaft 15 in a clevis 35. The brake shoe18 is supported by a cylindrical stem 36 having a block 38 therein whichis received by the clevis 35. The stem 36 passes freely through theblock 38 and terminates in a head 39, engageable with a wrench forremoval of the brake shoe 18. A pin 40 passes through a bore 41 in theclevis and through the block 38 permitting a limited amount of pivotalmovement therebetween as the control lever 13 pivots about the shaft 15.A compression spring 42 encircles the stem 36 and is interposed betweenthe block 38 and brake shoe 18 to resiliently bias the brake shoe 18toward the braking surface 32 to provide a somewhat gradual or cushionedapplication and release of the braking force, thereby reducing responsesensitivity to pivotal movement of lever 13. A sleeve 37 interposedbetween stem 36 and spring 42 precludes the possibility of excessivecompression of spring 42 which could eventually result in a fatiguefailure.

The brake shoe 18 is provided with a suitable lining 43 which engagesthe braking surface 32 on the'back ing plate 26. Guide tabs 44 and 45are fastened to the rear of the shoe 18 with screws 46 and 48respectively. The tabs 44 and 45 function to maintain positive alignmentbetween the plate 26 and the brake lining 43, ar-

resting any tendency for the brake shoe 18 to rotate about the stem 36.

The opposite end 50 of the control lever 13 carries the guide roller 16rotatably mounted on a shaft 51 extending perpendicularly from the lever13 and generally parallel with the spindle 25 and spool 24. A removablecollar 52 maintains the roller 16 on the shaft 51. The roller 16preferably includes a smooth cylindrical metal drum 53 over which thefilament F passes. As the filament F is payed out from the spool andpasses over the drum 53 it is maintained thereon by lateral flanges 54and 55. The roller 16 is preferably dimensioned to be as long as theheight of a spool 24 to insure the smooth and uniform withdrawal of thefilament F from the spool 24 without fouling.

A second, lever 14 is secured at one end on the inboard end of the shaft15, the levers 13 and 14 and the shaft 15 being pivotable with respectto the cylindrical housing 33 through which the shaft 15 passes. At theopposite end of the second lever 14, a yoke 56 is affixed as by a nut 58and bolt 59. The upper end of yoke 56 is connected to a piston rod 60 asby a pin 61. The piston rod portion 60 extends from an air cylinder 19which is preferably a low friction, rolling-diaphragm type of cylinder.The upper end portion 62 of the cylinder 19 is preferably pivotallyfixed as by an angled support brace 63 which may be fastened to the arm22, laterally extending from the hub 21, as by a nut 64 and screw 69.The cylinder 19 is supplied air at its upper end by an air hose 66connected to a suitable source of air (not shown). The arm 22 may alsocarry a stop for the control lever 13 which consists of a rubber bushing68 mounted on the arm 22 by the screw 69 passing through the bushing 68and secured by nut 64 and half nut 65.

The control lever 13, the lever 14, and the abovedescribed componentsconnected thereto are advantageously constructed of lightweight materialin order to reduce momentum in the system and thus further minimizehunting or oscillation tendencies of the control lever 13 which mightotherwise exist. For example, constructing the lever 13, 14 of heattreated aluminum has been found to satisfy the weight and strengthrequirements.

Having described the component parts of the device 10, the preferredoperation thereof is as follows. A spool 24 of filamentary material ismounted on the spindle 25 and the filament F is led counterclockwise, asdepicted in FIG. 1, from the top of the spool 24, under and around theguide roller 16 in a clockwise direction and to the take-up source (notshown). Prior to actuating the take-up, the control lever 13 and guideroller 16 will repose away from the spool 24, as depicted in phantom inFIG. 1. At this time, the brake shoe l8 urged by lining 43 will befirmly engaging the braking surface 32 thereby arresting rotation of thecircular backing plate 26 and spool 24 so that the filament F cannot bepayed out.

As the filament F is taken up, it will draw the guide roller 16 andcontrol lever 13 toward the spool 24 and in so doing, will reduce thefriction force between the brake lining 43 and the braking surface 32permitting the spool 24 and backing plate 26 torotate. Travel of thecontrol arm toward the spool 24, and concurrent reduction of the brakingforce is limited by the rubber bushing stop 68 in the event of anextreme variation in the take-up velocity.

The force exerted on control lever 13 by the filamentary material inengaging guide roller 16 is balanced against the friction between thelining 43 and braking surface 32 to maintain a constant tension in thefilament F. The tension from this force-balance system is, within normaloperating limits, independent of the coefficient of friction between thebraking surfaces. In the event the take up decreases in rate or ceases,the requisite amount of braking is immediately applied so there is neverany undesirable slack created in the filament F. Likewise, upon anincrease in the rate of takeup, the balance between the. braking forceand the force applied by the cylinder 19, permits a smooth and uniformrate of payout without stretching or jerking of the filament F.

By applying a relatively low amount of air pressure, e.g., approximatelyp.s.i., to the air cylinder 19, the piston rod 60, through the yoke 56,tends to urge the second lever 14 to rotate in a counterclockwisedirection, thereby applying a torsional force about the shaft 15, asdepicted in FIG. 1. Since this torsional force must be overcome by theforce exerted on lever arm 13 by guide roller 16 as produced by thefilament tension before the arm 13 rotates in a clockwise direction asseen in FIG. 1, it constitutes a biasing force substantiallyproportional to the tension in the filament. Thus, the filament tensionmay be selectively varied by controlling the air pressure in aircylinder 19.

Because the cylinder 19 normally does no work, a continuous flow of airthereto is not required. It need only be supplied at the necessarypressure quantity to achieve the desired tension in the filament whichit will retain and utilize until deliberately changed as for a differenttension more conducive to another filament or a change in operatingconditions. A plurality of the devices 10 could all be supplied from thesame regulated source concurrently to provide equivalent tension in aplurality of filaments. Such a source may be at least in part remotelylocated for convenient tension adjustment when required. Also, onaccount of the balance system tension in the filament F will remainsubstantially uniform from a full spool to empty, despite the fact thatthe spool rotates more rapidly as it is emptied, the commoneccentricities in spools, and other irregularities.

Thus, it should be evident that the disclosed device carries out theobjects of the invention set forth above. As apparent to those skilledin the art, modifications can be made without departing from the spiritof the invention herein disclosed and described, the scope of theinvention being limited solely by the scope of the attached claims.

What is claimed is:

l. A tension control device for spooled filamentary material comprising:a support structure, means rotatably supporting a spool in said supportstructure, means having a friction brake surface associated with saidmeans rotatably supporting a spool, a shaft journaled in said supportstructure, a first lever fixed on said shaft, filament guide meansmounted on one end of said first lever for engaging the filamentarymaterial payed out from said spool, brake means mounted on the other endof said first lever for engagement with said brake surface, means forresiliently biasing said brake means against said brake surfaceinterposed between said brake means and said first lever, a second leverfixed on said shaft, and an air cylinder having a fixedly mountedportion and a portion connected to said second lever for loading of saidfirst lever in order to balance the force acting on said first lever,exerted by the filamentary material against the filament guide means,and the friction between the brake means and brake surface and tomaintain a selected tension in said filament.

2. A tension control device, as in claim 1, wherein said first andsecond levers and means mounted thereon and connected thereto are ofrelatively light weight material.

3. A tension control device, as in claim 1, wherein said adjustablemeans has the fixedly mounted portion attached to said supportstructure.

4. A tension control device, as in claim 1, wherein said shaft isradially offset from said supporting means.

5. A tension control device, as in claim 4, wherein said supportstructure comprises a base plate and a hub mounting said spoolsupporting means having a radially extending arm mounting said shaft.

6. A tension control device, as in claim 3, wherein said supportstructure has a second radially extending arm on which said means forloading said first lever is mounted.

1. A tension control device for spooled filamentary material comprising: a support structure, means rotatably supporting a spool in said support structure, means having a friction brake surface associated with said means rotatably supporting a spool, a shaft journaled in said support structure, a first lever fixed on said shaft, filament guide means mounted on one end of said first lever for engaging the filamentary material payed out from said spool, brake means mounted on the other end of said first lever for engagement with said brake surface, means for resiliently biasing said brake means against said brake surface interposed between said brake means and said first lever, a second lever fixed on said shaft, and an air cylinder having a fixedly mounted portion and a portion connected to said second lever for loading of said first lever in order to balance the force acting on said first lever, exerted by the filamentary material against the filament guide means, and the friction between the brake means and brake surface and to maintain a selected tension in said filament.
 2. A tension control device, as in claim 1, wherein said first and second levers and means mounted thereon and connected thereto are of relatively light weight material.
 3. A tension control device, as in claim 1, wherein said adjustable means has the fixedly mounted portion attached to said support structure.
 4. A tension control device, as in claim 1, wherein said shaft is radially offset from said supporting means.
 5. A tension control device, as in claim 4, wherein said support structure comprises a base plate and a hub mounting said spool supporting means having a radially extending arm mounting said shaft.
 6. A tension control device, as in claim 3, wherein said support structure has a second radially extending arm on which said means for loading said first lever is mounted. 